Disparate response to metoclopramide therapy for gastric feeding intolerance in trauma patients with and without traumatic brain injury

Optimal caloric intake for critically ill patients: first, do no harm

Despite considerable efforts to define energy requirements for critically ill patients, no single method has been found to be precise and unbiased for all patients. As a result, clinicians have used various methods that may overestimate energy requirements for some patients. Provision of target caloric intake without regard to the complications of overfeeding, such as hyperglycemia, hypercapnia, or gastric feeding intolerance, could result in overall detrimental clinical outcome. Inadequate nutrition support is also associated with adverse clinical outcomes that necessitate optimization of delivery and tolerance of the nutrition regimen. A pivotal paper by Krishnan and colleagues published in 2003 brought these issues to the forefront of clinical practice. Key papers that support or refute the practice of "permissive underfeeding" are reviewed. Further research is necessary to determine the minimum amount of nutrition required to achieve a therapeutic benefit as well as to ascertain at what amount of additional nutrition intake offers no further improvement in clinical outcome.

Enteral nutrition in patients with severe traumatic brain injury: reasons for intolerance and medical management

Approximately, 50% of patients with severe traumatic brain injury (TBI) exhibit intolerance to enteral nutrition (EN). This intolerance hampers the survival and rehabilitation of this subpopulation to a great extent, and poses various difficulties for clinicians due to its complex underlying mechanisms. This review discusses the possible reasons for intolerance to EN following severe TBI, current trends in medical management, as well as other related issues that are experienced by many clinicians.

Practicalities of nutrition support in the intensive care unit: the usefulness of gastric residual volume and prokinetic agents with enteral nutrition

The provision of early nutrition therapy to critically ill patients is established as the standard of care in most intensive care units around the world. Despite the known benefits, tolerance of enteral nutrition in the critically ill varies and delivery is often interrupted. Observational research has demonstrated that clinicians deliver little more than half of the enteral nutrition they plan to provide. The main clinical tool for assessing gastric tolerance is gastric residual volume; however, its usefulness in this setting is debated. There are several strategies employed to improve the tolerance and hence adequacy of enteral nutrition delivery in the critically ill. One of the most widely used strategies is that of prokinetic drug administration, most commonly metoclopramide and erythromycin. Although there are new agents being investigated, none are ready for routine application in the critically ill and the benefits are still being established. This review investigates current practice and considers the literature on assessment of enteral tolerance and optimization of enteral nutrition in the critically ill.

Increased hypoglycemia associated with renal failure during continuous intravenous insulin infusion and specialized nutritional support

OBJECTIVE

To evaluate glycemic control for critically ill, hyperglycemic trauma patients with renal failure who received concurrent intensive insulin therapy and continuous enteral nutrition (EN) or parenteral nutrition (PN).

METHODS

Adult trauma patients with renal failure who were given EN or PN concurrently with continuous graduated intravenous regular human insulin (RHI) infusion for at least 3 d were evaluated. Our conventional RHI algorithm was modified for those with renal failure by allowing greater changes in blood glucose (BG) concentrations before the infusion rate was escalated. BG concentration was determined every 1 to 2 h while receiving the insulin infusion. BG control was evaluated on the day before RHI infusion and for a maximum of 7 d while receiving RHI. Target BG during the RHI infusion was 70 to 149 mg/dL (3.9 to 8.3 mmol/L). Glycemic control and incidence of hypoglycemia for those with renal failure were compared with a historical cohort of critically ill, hyperglycemic trauma patients without renal failure given our conventional RHI algorithm.

RESULTS

Twenty-one patients with renal failure who received the modified RHI algorithm were evaluated and compared with 40 patients without renal failure given our conventional RHI algorithm. Average BG concentration was significantly greater for those with renal failure (133±14 mg/dL or 7.3±0.7 mmol/L) compared with those without renal failure (122±15 mg/dL or 6.8±0.8 mmol/L), respectively (P<0.01). Patients with renal failure showed worsened glycemic variability, with 16.1±3.3 h/d within the target BG range, 6.9±3.2 h/d above the target BG range, and 1.4±1.1 h/d below the target BG range compared with 19.6±4.7 h/d (P<0.001), 3.4±3.0 h/d (P<0.001), and 0.7±0.8 h/d (P<0.01) for those without renal failure, respectively. Moderate hypoglycemia (<60 mg/dL or<3.3 mmol/L) occurred in 76% of patients with renal failure compared with 35% without renal failure (P<0.005). Severe hypoglycemia (BG<40 mg/dL or<2.2 mmol/L) occurred in 29% of patients with renal failure compared with none of those without renal failure (P<0.001).

CONCLUSION

Despite receiving a modified RHI infusion, critically ill trauma patients with renal failure are at greater risk for developing hypoglycemia and have more glycemic variability than patients without renal failure.